Laser-induced fluorescence of CsH: The X1Σ+ state dissociation energy

Laser-induced fluorescence of CsH from the A¹Σ⁺ electronic state to the X¹Σ⁺ state was recorded using high-resolution Fourier transform spectrometry. Ground-state vibrational levels were observed from ν″ = 1 to the dissociation limit. These measurements showed anomalies in the X¹Σ⁺ potential energy curve due to the avoided crossing of ionic and covalent potential curves. Accurate molecular constants were derived for the lower X¹Σ⁺ vibrational levels. The observation of a quasibound level gave the first experimental determination of the dissociation energy (in cm^?1): 14802 ? D_c ? 14813.